Commentary: Meta-analysis of trials comparing antidepressants with active placebos

1998 ◽  
Vol 172 (3) ◽  
pp. 232-234 ◽  
Author(s):  
David Healy

This attempt to establish treatment effect sizes follows a tradition, which dates back over 20 years, of assessing the effects of antidepressant treatment under ‘blinder conditions'. The method adopted by Moncrieff et al has some merit but involves a recourse to studies, many of which are over 30 years old. While the studies may not be seriously flawed, it is difficult to have much confidence in them. None appears to have included what the authors describe as an ‘inert’ placebo, which strictly speaking would be a non-drug arm to the study. The number of studies is small. The dose of drugs used, which might be expected to have some influence on outcomes, is not mentioned. Finally, as experience with studies in obsessive-compulsive disorder indicates, treatment effect sizes can vary substantially from one decade to another –most probably because different individuals are recruited although all may apparently meet the same diagnostic criteria.

2009 ◽  
Vol 195 (5) ◽  
pp. 393-402 ◽  
Author(s):  
Joaquim Radua ◽  
David Mataix-Cols

BackgroundSpecific cortico-striato-thalamic circuits are hypothesised to mediate the symptoms of obsessive–compulsive disorder (OCD), but structural neuroimaging studies have been inconsistent.AimsTo conduct a meta-analysis of published and unpublished voxel-based morphometry studies in OCD.MethodTwelve data-sets comprising 401 people with OCD and 376 healthy controls met inclusion criteria. A new improved voxel-based meta-analytic method, signed differential mapping (SDM), was developed to examine regions of increased and decreased grey matter volume in the OCD group v. control group.ResultsNo between-group differences were found in global grey matter volumes. People with OCD had increased regional grey matter volumes in bilateral lenticular nuclei, extending to the caudate nuclei, as well as decreased volumes in bilateral dorsal medial frontal/anterior cingulate gyri. A descriptive analysis of quartiles, a sensitivity analysis as well as analyses of subgroups further confirmed these findings. Meta-regression analyses showed that studies that included individuals with more severe OCD were significantly more likely to report increased grey matter volumes in the basal ganglia. No effect of current antidepressant treatment was observed.ConclusionsThe results support a dorsal prefrontal–striatal model of the disorder and raise the question of whether functional alterations in other brain regions commonly associated with OCD, such as the orbitofrontal cortex, may reflect secondary compensatory strategies. Whether the reported differences between participants with OCD and controls precede the onset of the symptoms and whether they are specific to OCD remains to be established.


2020 ◽  
Author(s):  
Sofia Persson ◽  
Alan Yates ◽  
Klaus Kessler ◽  
Ben Harkin

Even though memory performance is a commonly researched aspect of Obsessive-Compulsive Disorder (OCD), a coherent and unified explanation of the role of specific cognitive factors has remained elusive. To address this, the present meta-analysis examined the predictive validity of Harkin and Kessler’s (2011) Executive Function (E), Binding Complexity (B) and Memory Load (L) Classification System with regards to affected vs. unaffected memory performance in OCD. We employed a multi-level meta-analytic approach (Viechtbauer, 2010) to accommodate the interdependent nature of the EBL model and interdependency of effect sizes (305 effect sizes from 144 studies, including 4424 OCD patients). Results revealed that the EBL model predicted memory performance, i.e., as EBL demand increases, those with OCD performed progressively worse on memory tasks. Executive function was the driving mechanism behind the EBL’s impact on OCD memory performance and negated effect size differences between visual and verbal tasks in those with OCD. Comparisons of sub-task effect sizes were also generally in accord with the cognitive parameters of the EBL taxonomy. We conclude that standardised coding of tasks along individual cognitive dimensions and multi-level meta-analyses provides a new approach to examine multi-dimensional models of memory and cognitive performance in OCD and other disorders.


BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e050329
Author(s):  
Johannes Julian Bürkle ◽  
Johannes Caspar Fendel ◽  
Stefan Schmidt

IntroductionCognitive–behavioural therapy (CBT) with exposure and response prevention is the recommended standard for the treatment of obsessive–compulsive disorder (OCD). However, a high proportion of patients refuse this treatment, do not respond or relapse shortly after treatment. Growing evidence suggests that mindfulness-based and acceptance-based programmes (MABPs) are an effective option for the treatment of OCD. This systematic review and meta-analysis will examine the effectiveness of MABPs in treating OCD. We also aimed to explore potential moderators of the programmes’ effectiveness.Methods and analysisWe will systematically search MEDLINE, Embase, PsycINFO, PSYINDEX, Web of Science, CINAHL and Cochrane Register of Controlled Trials (no language restrictions) for studies that evaluate the effect of MABPs on patients with OCD. We will conduct backward and forward citation searches of included studies and relevant reviews and contact corresponding authors. The primary outcome will be pre-post intervention change in symptom severity. A secondary outcome will be change in depressive symptoms. Two reviewers will independently screen the records, extract the data and rate the methodological quality of the studies. We will include both controlled and uncontrolled trials. Randomised controlled trials will be meta-analysed, separately assessing between-group effects. A second meta-analysis will assess the within-group effect of all eligible studies. We will explore moderators and sources of heterogeneity such as the specific programme, study design, changes in depressive symptoms, hours of guided treatment, control condition and prior therapy (eg, CBT) using metaregression and subgroup analyses. We will perform sensitivity analyses using follow-up data. A narrative synthesis will also be pursued. We will use the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to assess the quality of the evidence.Ethics and disseminationEthical approval is not required. Results will be published in peer-reviewed journals and presented at international conferences.


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